Lignin is the most abundant heterogeneous aromatic polymer present on planet Earth and is recalcitrant to degradation due to its complex structure, therefore, imposing a challenge to biorefinery procedures. Identifying new microbial strains with the potential to valorize lignin into useful compounds is indispensable to achieving green sustainable consumption. In this study, a novel Pseudomonas strain designated as Hu109A was isolated from the termite gut and the genome was sequenced and analyzed further. The genome contains a circular chromosome with the size of 5,131,917 bp having a GC content of 62.6% and 4698 genes. Genome annotation reveals that the strain possesses lignin-oxidizing enzymes such as DyP-type peroxidases, laccase, dioxygenase, and aromatic degradation gene clusters. The genome also contains O-methyltransferases which function in accelerating the lignin degradation by methylating the free hydroxyl phenolic compounds which in high concentration can inhibit the lignin peroxidase. Furthermore, the genome exhibits two gene clusters encoding the enzymes related to polyhydroxyalkanoates (PHA) synthesis. Pseudomonas strains are generally assumed to produce medium chain length PHAs (mcl-PHAs) only, however, strain Hu109A contains both Class II PHA synthase genes involved in mcl-PHAs and Class III PHA synthase gene involved in short-chain length PHAs (scl-PHAs). Gas Chromatography-Mass Spectrometry (GC-MS) analysis showed that using 1 g/L lignin as the sole carbon source, the maximum production of PHA observed was 103.68 mg/L, which increased to 186 mg/L with an increase in lignin concentration to 3 g/L. However, PHA production while using glucose as the sole carbon source was significantly lower than the lignin source, and maximum production was 125.6 mg/L with 3 g/L glucose. The strain Hu109A can tolerate a broad range of solvents including methanol, isopropanol, dimethylformamide, and ethanol, revealing its potential for industrial applications.

木质素是地球上存在的最丰富的异质芳香族聚合物，并且由于其复杂的结构而难以降解，因此对生物精炼程序提出了挑战。识别具有将木质素转化为有用化合物的潜力的新微生物菌株对于实现绿色可持续消费是必不可少的。在这项研究中，一种新型的假单胞菌从白蚁肠道中分离出名为 Hu109A 的菌株，并对基因组进行测序和进一步分析。该基因组包含一个大小为5,131,917 bp、GC含量为62.6%的环状染色体和4698个基因。基因组注释显示该菌株具有木质素氧化酶，如 DyP 型过氧化物酶、漆酶、双加氧酶和芳香降解基因簇。基因组还含有O-甲基转移酶，通过甲基化游离羟基酚类化合物加速木质素降解，高浓度时可抑制木质素过氧化物酶。此外，基因组表现出两个基因簇，编码与聚羟基链烷酸酯 (PHA) 合成相关的酶。假单胞菌属通常假设菌株仅产生中等链长 PHA (mcl-PHA)，然而，菌株 Hu109A 包含参与 mcl-PHA 的 II 类 PHA 合酶基因和参与短链长度 PHA (scl-PHA) 的 III 类 PHA 合酶基因）。气相色谱-质谱 (GC-MS) 分析表明，以 1 g/L 木质素为唯一碳源，观察到 PHA 的最大产量为 103.68 mg/L，随着木质素浓度的增加增加到 186 mg/L至 3 克/升。然而，使用葡萄糖作为唯一碳源时的 PHA 产量显着低于木质素源，在 3 g/L 葡萄糖时最大产量为 125.6 mg/L。Hu109A菌株可以耐受包括甲醇、异丙醇、二甲基甲酰胺和乙醇在内的多种溶剂，显示出其在工业应用中的潜力。